Pentagastrin (trade name Peptavlon) is a synthetic polypeptide that has effects like gastrin when given parenterally.

[2] It stimulates the secretion of gastric acid, pepsin, and intrinsic factor, and has been used as a diagnostic aid as the pentagastrin-stimulated calcitonin test.

[citation needed] It has been used to stimulate ectopic gastric mucosa for the detection of Meckels diverticulum by nuclear medicine.

In these patients, injecting pentagastrin will cause calcitonin levels to rise significantly above the normal or basal range.

[4] After a total thyroidectomy for medullary thyroid carcinoma, the pentagastrin-stimulated calcitonin release can be used to detect residual parafollicular C-cells.